
I H ' 



HHH 









* /. 








A* 




° • * * .0 







<V s • • » •. V" *** * ' 1 A t£^ 













^°^ 























^^ 







>^ .» J 









*bK 











: *W* ** 









° > • j§^^^a - A 



0^ »VUL% "> 





v # i * • 



,% -£ 






0^ o^»^ ^*0 











1* f 








^vT/AiP * r<i. * «<ilv\\sjv' * \ 





"^ A> <^«. A ^l • * s \ ' <\» ° • » «G o 







'^ 



°- -.*S»: „*°-v "-3 










^ .-iaSfe*. V./ /jfite\ wV 




^ °J5i' ***** 





&$ 



4 : /**> 




'-•' A ' V'^'V^ °°^ 

V'^'V V^V v*?^/ 



'■' 




VV 




,* 



♦ o 



A v 



» . <*>. 






1C 9080 



Bureau of Mines Information Circular/1986 



Economic Evaluation of Horizontal 
Borehole Drilling for Methane 
Drainage From Coalbeds 



By Eugene C. Baker, Roy H. Grau III, 
and Gerald L. Finfinger 




UNITED STATES DEPARTMENT OF THE INTERIOR 






Information Circular 9080 



Economic Evaluation of Horizontal 
Borehole Drilling for Methane 
Drainage From Coalbeds 



By Eugene C. Baker, Roy H. Grau III, 
and Gerald L. Finfinger 




UNITED STATES DEPARTMENT OF THE INTERIOR 
Donald Paul Hodel, Secretary 

BUREAU OF MINES 
Robert C. Horton, Director 






r>o< 



tfW 




Library of Congress Cataloging in Publication Data: 



Baker, E. C. (Eugene C.) 

Economic evaluation of horizontal borehole drilling for methane 
drainage from coalbeds. 

(Bureau of Mines Information circular; 9080) 

Bibliography: p. 10. 

Supt. of Docs, no.: I 28.27:9080. 



1. Methane industry -Alabama -Cost effectiveness. 2. Gas well drilling -Alabama -Cost 
effectiveness. 3. Coal mines and mining-Alabama-Safety measures. I. Grau, Roy H. II. 
Finfinger, Gerald L. III. Title. IV. Series: Information circular (United States. Bureau of 
Mines); 9080 



TN295.U4 [HD9579.M43U6] 622 s [338.2'3] 



86-600068 



CONTENTS 

Page 

Abstract 1 

Introduction 2 

General mining plan 2 

Horizontal drilling plan 2 

Gas drainage plan 3 

Borehole locations and production 3 

Gas collection and transmission system 5 

Methane gas sensing system 5 

Surface equipment 8 

Basis for economic evaluation 8 

Assumptions 8 

Estimated capital investment. 8 

Depreciated and expensed items 9 

Estimated annual operating cost. 9 

Cash flow analysis 9 

Summary of discounted cash flow 10 

Conclusions 10 

References 10 

Appendix. — Cost and analysis tables.. 11 

ILLUSTRATIONS 

1 . Mine plan and borehole location 6 

2. Gas transmission pipeline and borehole location 7 

3. Gas production decline curves 8 

TABLES 

1. Annual gas recovery, 1985-90 3 

2. Annual gas recovery, 1986-90 4 

3. Annual gas recovery, 1987-90 4 

4. Annual gas recovery, 1988-90 5 

5. Annual gas recovery, 1989-90 5 

A-l. Estimated initial capital investment 11 

A-2. Estimated deferred capital investment 11 

A-3. Drill string 12 

A-4. Methane gas collection system 12 

A-5. Methane gas transmission system 13 

A-6. Methane gas sensing system 14 

A-7. Estimated capital investment summary 14 

A-8. Depreciation schedule 14 

A-9. Estimated annual operating cost 15 

A-10. Cash flow analysis 17 

A-ll. Summary of discounted cash flow 18 





UNIT OF MEASURE 


ABBREVIATIONS USED 


IN THIS REPORT 


d/yr 


day per year 


kW/h 


kilowatt per hour 


ft 


foot 


Mft 3 


thousand cubic feet 


ft2 


square foot 


Mft 3 /d 


thousand cubic feet per day 


ft3 


cubic foot 


MMft 3 /d 


million cubic feet per day 


h 


hour 


pet 


percent 


hp 


horsepower 


pct/yr 


percent per year 


h/shift 


hour per shift 


psig 


pound per square inch, gauge 


h/yr 


hour per year 


shifts/d 


shifts per day 


in 


inch 


yr 


year 


kW'h 


kilowatt hour 







ECONOMIC EVALUATION OF HORIZONTAL BOREHOLE 
DRILLING FOR METHANE DRAINAGE FROM COALBEDS 



By Eugene C. Baker, 1 Roy H. Grau III, 2 and Gerald L. Finfinger 3 



ABSTRACT 

The potential profitability of a horizontal borehole drilling program 
for recovering methane gas in an Alabama coalbed for 6 yr in advance of 
mining is estimated in this Bureau of Mines report. 

A cash flow analysis based on estimated capital investments, annual 
operating costs, and the selling price of methane gas was used to deter- 
mine the net income and net cash flows for each year of operation. Sub- 
sequently, the annual net cash flows were capitalized to determine the 
discounted cash flow rate of return. 

Findings indicate that a 25.08-pct interest rate of return on invest- 
ment could be realized from the sale of methane gas in excess of 3 bil- 
lion ft 3 during the years 1985 through 1990 at a mine site price of 



$2.25/Mft 3 . 



'Physical scientist. 
^Mining engineer. 
•^Supervisory geologist. 
Pittsburgh Research Center, Bureau of Mines, Pittsburgh, PA. 



INTRODUCTION 



Release of methane gas from coalbeds is 
a serious safety hazard in underground 
coal mining. The Bureau of Mines has pi- 
oneered the development of drilling hori- 
zontal boreholes for draining methane 
gas from coalbeds in advance of mining 
O -4). 4 

Industry has shown increasing interest 
in methane drainage since 1977, primarily 
because of the decreasing supply and in- 
creasing price of methane gas. The de- 
velopment of horizontal borehole drilling 
technology, improved drilling equipment, 
computerized methane sensing and control, 
systems, and definitive guidelines for 
installing and maintaining underground 
gas transmission pipelines has provided 
added incentive for coal producing com- 
panies to invest capital in methane 
drainage systems (5-7). 

Underground horizontal boreholes in 
coal seams have great potential for 



producing large-volume flows of methane. 
Every foot drilled in the coalbed from 
underground locations is productive, and 
gas flows increase as hole length in- 
creases. In using horizontal boreholes, 
dewatering pumps are not necessary be- 
cause gas pressure forces water out of 
the hole so that methane can be recovered 
through the use of simple and inexpensive 
gas-water separators. 

The quantity of available gas and po- 
tential drainage rates used in this re- 
port were based on recent tests performed 
at an underground mine in Alabama. The 
number of horizontal boreholes that could 
be drilled each year was based on the 
company's current and future coal produc- 
tion rate. 

To current knowledge, this report is 
the first to examine the economic feasi- 
bility of recovering and selling methane 
to gas transmission companies. 



GENERAL MINING PLAN 



The operating underground mine used in 
this study is located in Tuscaloosa Coun- 
ty, AL, and is producing coal from the 
Mary Lee group of coalbeds in the Warrior 
Basin. Overburden thickness at this lo- 
cation is approximately 2,000 ft; coal 
seam thicknesses are about 6 ft for the 
Blue Creek and 1.5 ft for the Mary Lee 
(8). 

The coal mine is developed primarily 
for longwall mining using continuous 



miners to drive four entry sections for 
longwall development. The four entries 
are mined on 120-ft centers and are ap- 
proximately 20 ft wide. The continuous 
mining sections employ split ventilation 
by using the outside two entries as re- 
turn airways and the middle two entries 
as belt and intake track airways. The 
longwall panels vary in length and are 
generally 600 ft wide. 



HORIZONTAL DRILLING PLAN 



One drilling unit would be operated two 
shifts a day for 240 days. Maintenance 
of the equipment would be done concur- 
rently with drilling. Twenty-three bore- 
holes would be drilled the first year, 

^Underlined numbers in parentheses re- 
fer to items in the list of references at 
the end of this report. 



and 22, 19, 13, and 12 boreholes, respec- 
tively, would be drilled in the next 4 
yr, based on the mine development plan. 
Drilling would be accomplished by normal 
rotary drilling techniques as described 
in previous Bureau publications (_3, 9- 
10). Cost of the drilling equipment is 
$207,950 as shown in appendix tables A-l 
and A- 2. 



GAS DRAINAGE PLAN 



BOREHOLE LOCATIONS AND PRODUCTION 

The horizontal boreholes used for 
methane drainage are drilled with an 
underground electrohydraulic drill unit 
as described in a previous Bureau publi- 
cation (2^). The 3-1/2-in-diam boreholes 
are approximately 1,000 ft long. All 
boreholes are drilled from return airways 
and are started in approximately the mid- 
dle of the coalbed. Boreholes drilled 
from active continuous mining sections 
generally are located as close to the 
face as possible without causing inter- 
ference with production. The drilling of 
boreholes for this program is started at 
an approximate angle of 15° from the di- 
rection of mining advance. This reduces 
the probability of borehole interception 
of areas being mined by the continu- 
ous miners. The remaining boreholes are 



located in inactive areas of the mine and 
are spaced throughout the mine perimeter. 
The horizontal borehole locations are 
shown in figures 1 and 2. Figure 1 rep- 
resents the mine plan and additional hor- 
izontal boreholes on an annual basis. 

The gas produced from the horizontal 
boreholes was estimated from actual data 
collected from methane drainage studies 
of the Mary Lee Group. By averaging data 
from previously drilled horizontal bore- 
holes, estimated gas production decline 
curves shown in figure 3 were prepared. 
Two production decline curves were used, 
depending on the orientation of the bore- 
holes with respect to the highly perme- 
able face cleat direction. Subsequently, 
the production decline curves were used 
for determining annual gas drainage for 
each of the horizontal boreholes (tables 
1-5). 



TABLE 1. - Annual gas recovery, 1985-90, thousand cubic feet 



1985 
boreholes 


1985 


1986 


1987 


1988 


1989 


1990 


3 

4 

6 

7 

8 

9 

11 

13 

14 

15 

16 

17 

18 

19 

20 

21 

23 


21, 

21, 

21, 

21, 

21, 

21, 

21, 

21, 

21, 

21, 

21. 

21 

21 

21 

21 

21 

21 

21 

21 

21 

21 

21 

21 


000 

600 

600 

600 

000 

000 

000 

000 

000 

000 

000 

000 

000 

,000 

,000 

000 

,000 

,000 

,000 

000 

,600 

,000 

,000 


11,700 

5,800 

5,800 

5,800 

11,700 

11,700 

11,700 

11,700 

11,700 

11,700 

11,700 

11,700 

11,700 

NAp 

11,700 

11,700 

11,700 

11,700 

11,700 

11,700 

NAp 

11,700 

11,700 


8,500 

4,400 

4,400 

4,400 

8,500 

NAp 

8,500 

8,500 

NAp 

NAp 

NAp 

8,500 

8,500 

NAp 

8,500 

8,500 

NAp 

NAp 

NAp 

8,500 

NAp 

8,500 

8,500 


6,000 

3,300 

3,300 

3,300 

6,000 

NAp 

NAp 

NAp 

NAp 

NAp 

NAp 

6,000 

6,000 

NAp 

6,000 

NAp 

NAp 

NAp 

NAp 

NAp 

NAp 

6,000 

6,000 


3,400 

1,700 

1,700 

1,700 

3,400 

NAp 

NAp 

NAp 

NAp 

NAp 

NAp 

3,400 

3,400 

NAp 

NAp 

NAp 

NAp 

NAp 

NAp 

NAp 

NAp 

3,400 

3,400 


1,000 
500 
500 
500 

1,000 
NAp 
NAp 
NAp 
NAp 
NAp 
NAp 

1,000 
NAp 
NAp 
NAp 
NAp 
NAp 
NAp 
NAp 
NAp 
NAp 

1,000 

1,000 


Total. 


485 


,400 


228,000 


106,700 


51,900 


25,500 


6,500 



NAp Not applicable. 



TABLE 2. - Annual gas recovery, 1986-90, 
thousand cubic feet 



1986 
boreholes 



1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

16 

17 

18 

19 

20 

21 

22 

Subto 

Carryove 

Total 



tal 
r. . 



1986 



21 
21 
21 
21 
21 
21 
21 
21 
21 
21 
21 
21 
21 
21 
21 
21 
21 
21 
21 
21 
21 
21 



464 
228 



692 



000 
000 
000 
000 
600 
600 
000 
000 
000 
000 
000 
000 
000 
000 
000 
000 
000 
000 
000 
600 
600 

ooo 



400 
000 



400 



1987 



11 
11 
11 
11 
5 
5 
11 
11 
11 
11 
11 
11 
11 
11 
11 
11 
11 
11 
11 
5 
5 
11 



233 
106 



340 



700 
700 
700 
700 
800 
800 
700 
700 
700 
700 
700 
700 
700 
700 
700 
700 
700 
700 
700 
800 
800 
700 



800 
700 



500 



1988 



NAp 

NAp 

NAp 

NAp 

4,400 

4,400 

NAp 

NAp 

NAp 

NAp 

8,500 

8,500 

8,500 

NAp 

8,500 

8,500 

8,500 

NAp 

NAp 

4,400 

4,400 

8,500 



77,100 
51,900 



129,000 



1989 



NAp 

NAp 

NAp 

NAp 

3,300 

3,300 

NAp 

NAp 

NAp 

NAp 

NAp 

6,000 

6,000 

NAp 

NAp 

NAp 

NAp 

NAp 

NAp 

NAp 

NAp 

6,000 



24,600 
25,500 



50,100 



1990 



NAp 
NAp 
NAp 
NAp 
1,700 
1,700 
NAp 
NAp 
NAp 
NAp 
NAp 
NAp 
NAp 
NAp 
NAp 
NAp 
NAp 
NAp 
NAp 
NAp 
NAp 
3,400 



6,800 
6,500 



13,300 



NAp Not applicable. 
TABLE 3. - Annual gas recovery, 1987-90, thousand cubic feet 



1987 
boreholes 


1987 


1988 


1989 


1990 


1987 
boreholes 


1987 


1988 


1989 


1990 


3 

6 

8 


21,000 
21,000 
21,000 
21,000 
21,000 
21,000 
21,000 
21,000 
21,000 
21,000 
21,000 


11,700 
11,700 
11,700 
11,700 
11,700 
11,700 
11,700 
11,700 
11,700 
11,700 
11,700 


NAp 

8,500 

8,500 

NAp 

8,500 

8,500 

8,500 

NAp 

NAp 

NAp 

NAp 


NAp 

NAp 

NAp 

NAp 

6,000 

6,000 

6,000 

NAp 

NAp 

NAp 

NAp 


13 

14 

Subtotal 

Carryover. 

Total. .. 


21,000 
21,000 
21,000 
21,000 
21,000 
21,000 
21,000 
21,000 


11,700 
11,700 
11,700 
11,700 
11,700 
11,700 
11,700 
11,700 


8,500 
8,500 
8,500 
8,500 
8,500 
8,500 
8,500 
8,500 


6,000 
6,000 
NAp 
NAp 
6,000 
NAp 
NAp 
NAp 


10 


399,000 
340,500 


222,300 
129,000 


110,500 
50,100 


36,000 
13,300 




739,500 


351,300 


160,600 


49,300 



NAp Not applicable. 



TABLE 4. - Annual gas recovery, 1988-90, 
thousand cubic feet 



1988 
boreholes 



1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

Subtotal. . . 

Carryover 

Total 



1988 



21 
21 
21 
21 
21 
21 
21 
21 
21 
21 
21 
21 
21 



273 
351 



624 



000 
000 
000 
000 
000 
000 
000 
000 
000 
600 
000 
000 
000 



600 
300 



900 



1989 



11,700 
11,700 
11,700 
11,700 
11,700 
11,700 
11,700 
11,700 
11,700 
5,800 
11,700 
11,700 
11,700 



146,200 
160,600 



306,800 



1990 



8,500 

NAp 

8,500 

8,500 

8,500 

8,500 

8,500 

8,500 

NAp 

4,400 

NAp 

8,500 

8,500 



80,900 
49,300 



130,200 



NAp Not applicable 



TABLE 5. - Annual gas recovery, 1989-90, 
thousand cubic feet 



1989 boreholes 

1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

Subtotal 

Carryover 

Total 



1989 



21,000 
21,000 
21,000 
21,000 
21,000 
21,000 
21,000 
21,000 
21,000 
21,000 
21,000 
21,000 



252,000 
306,800 



558,800 



1990 



11,700 
11,700 
11,700 
11,700 
11,700 
11,700 
11,700 
11,700 
11,700 
11,700 
11,700 
11,700 



140,400 
130,200 



270,600 



GAS COLLECTION AND TRANSMISSION SYSTEM 

The gas collection system gathers the 
methane from the coal face, separates gas 
from water prior to its entering the 



transmission system, and measures the gas 
production. The gas collection system 
for each borehole comprises a stand- 
pipe, a water trap, a venturi meter, and 
assorted valves, fittings, and pipes (2). 
The total costs of the gas collection and 
transmission systems are $132,910 and 
$584,700, respectively, as shown in ta- 
bles A-4 and A-5. 

The underground gas transmission system 
is constructed of 6- and 8-in-diam poly- 
ethylene pipe and 10-in-diam steel pipe. 
The 6-in-diam polyethylene pipe would 
be used for transporting the gas from 
each mining section, and the 8-in-diam 
polyethylene pipe would serve as the 
main line of the system. Each year addi- 
tional polyethylene pipe would be added 
as needed to connect with newly drilled 
boreholes. The 8-in-diam polyethylene 
pipe would connect with the 10-in-diam 



steel pipe, 
the mine's 
porting the 



which would be anchored to 
return air shaft for trans- 
collected gas to the sur- 
face. For emergency shutdown and mainte- 
nance, all underground gas lines would be 
equipped with manual shutoff valves. The 
pipeline sizes were selected to minimize 
pressure losses based on expected gas 
flows and pipeline lengths. 

METHANE GAS SENSING SYSTEM 

The underground gas collection and 
transmission system is continuously moni- 
tored for leaks by methane sensors in- 
stalled at strategic locations through- 
out the mine. The sensors are connected 
through a series of control devices to 
pneumatically activated valves at each 
horizontal borehole. The valves pneumat- 
ically close if unsafe conditions occur, 
thereby automatically stopping the gas 
flow from each borehole. The safety sys- 
tem requires the installation of methane 
sensors, a microprocessor, a data sta- 
tion, and a 3/4-in-diam polyvinyl chlo- 
ride (PVC) pipeline which delivers 



LEGEND 
Panel Borehole and 



Mine boundary 

Lj 




^ -r r 

FIGURE 1.— Mine plan and borehole location. 



LEGEND 

Borehole and 
number 

Year 
3 1985 



3) 1986 




Manual valve 
/^"8-in main line 




E\ 



© 



S/ 



©/ 



A7 



■<H 



23 




17 



j^ 






jZ. 



■21 



<g> 



2,000 
1 1 1 

Scale, ft 



4' 3 2 

FIGURE 2.— Gas transmission pipeline and borehole location. 



"I 1 1 1 1 — 

KEY 
Hole parallel to face cleat 
Hole perpendicular to face cleat 




2.0 2.5 3.0 

TIME, yr 

FIGURE 3.— Gas production decline curves. 



compressed air to the pneumatic valve. 
The system is described in detail in a 
previous publication (9). The total cost 



of the pipeline sensing system is 
$455,910 as shown in table A-6. 

SURFACE EQUIPMENT 

The main function of the surface equip- 
ment is to assure continuous quality con- 
trol of the recovered gas and to provide 
sufficient gas pressure to access a natu- 
ral gas transmission system. Basic sur- 
face equipment includes a 168-hp com- 
pressor capable of handling 2 MMft 3 /d at 
30-psig discharge, a gas analyzer, a 
flowmeter, a temperature monitor, and 
three flame arrestors installed for fire 
safety control. The surface equipment 
would be continuously operated and would 
require daily inspection and periodic 
maintenance. Cost of the surface items 
is $209,350 as shown in table A-l. 



BASIS FOR ECONOMIC EVALUATION 



ASSUMPTIONS 



1. Project development and the pur- 
chase of initial property were completed 
in 1984 by company personnel. The pur- 
chase price of surface building equipment 
and drilling equipment includes installa- 
tion and setup by the vendor. 

2. The horizontal drilling program 
will be conducted for 5 yr, and methane 
gas will be recovered and marketed for 
6 yr. The producing company owns the gas 
rights. 

3. Costs of initial and deferred capi- 
tal equipment, operating materials, sup- 
plies, and electric power were obtained 
from suppliers. 

4. Tangible assets were depreciated 
over 5 yr using the accelerated cost 
recovery system rates, and salvage val- 
ue is recovered on deferred capital 
investments. 

5. Labor wages are escalated from 
third-quarter rates quoted in the Bitumi- 
nous Coal Wage Agreement of 1981; salar- 
ies of supervisors and technicians are 
escalated on the basis of estimates ob- 
tained from industry. 

6. Working capital is based on the 
cost of operations for 3 months. The 
value of working capital at the end of 
the gas drainage program will be equal to 
its initial value. 



7. Equity capital will be used to fi- 
nance the project. 

ESTIMATED CAPITAL INVESTMENT 

The estimated capital investment in- 
cludes initial expenditures in 1984 and 
deferred capital costs in 1985 through 
1988. The items included in the total 
capital investment are detailed in table 
A-l and summarized in table A-7. 

Project development is an intangible 
cost that is not depreciable. In the 
cash flow analysis (table A-10) develop- 
ment costs are expensed in 1984 and car- 
ried forward to 1985, which is the first 
year of operation and revenue. 

The surface building and equipment and 
drilling equipment detailed in table A-l 
were purchased in 1984. They are to be 
placed in service in 1985 and be fully 
depreciated by the end of the borehole 
drilling phase of the project in 1989. 

The quantity and cost per year of ini- 
tial and deferred items included in the 
methane gas collection system, trans- 
mission system, and sensing system are 
detailed in tables A-4, A-5, and A-6. 
These items would be purchased during the 
year prior to the start of borehole 
drilling and gas drainage. The intangi- 
ble indirect capital costs are shown in 
the year incurred. 



Based on the mine development plan, the 
number of boreholes to be drilled each 
year from 1985 through 1989 is 23, 22, 
19, 13, and 12 respectively, as shown in 
tables 1-5. The boreholes that show no 
drainage are either depleted of gas or 
mined through. As a result, the equip- 
ment and materials of the gas collection 
system, transmission system, and sensing 
system that were used on these boreholes 
will be dismantled, moved, and installed 
for use on boreholes that will be drilled 
in subsequent years. The capital cost of 
the initial and deferred systems includes 
the purchase price and installation of 
new items added each year and the disas- 
sembly, moving, and installation costs of 
the items recovered each year from non- 
producing holes previously drilled. 

DEPRECIATED AND EXPENSED ITEMS 

Initial and deferred direct capital in- 
vestment items shown in table A-l are de- 
preciated in table A-8 using accelerated 
cost recovery rates of 15, 22, 21, 21, 
and 21 pet for 1986-90, respectively. 

Initial and deferred indirect capital 
investment items including administra- 
tion, overhead, and contingency are ex- 
pensed as intangible costs in the cash 
flow analysis (table A-10). 

The systems used for gas collection, 
transmission, and sensing will be placed 
in service in 1985 and 1986 and are as- 
sumed to be fully depreciated in 5 yr. 
Additional items will be placed in ser- 
vice in these systems in the following 
3 yr but will not be fully depreciated. 
Salvage value equal to book value is 
taken on the systems because they will be 
used in subsequent gas drainage projects. 

ESTIMATED ANNUAL OPERATING COST 

Horizontal drilling of boreholes into 
an underground coalbed for the drainage 
of methane gas will continue for 240 d/yr 
for 5 yr. Methane gas will drain from 
the boreholes for 6 yr, during which time 
the surface, drilling, and gas sensing 
equipment will be monitored and main- 
tained. The estimated annual operating 
costs are detailed in table A-9. 



The pay for wage and salaried personnel 
is escalated 8 pct/yr for the first 3 yr 
of operation and 10 pct/yr for the last 
3 yr. Shift differential pay of $0.30/h 
and $0.40/h for the second and third 
shift is included in total wages for op- 
erating and maintenance labor. 

The initial and escalated costs of sup- 
plies and parts are based on estimates 
provided by suppliers, and electric power 
is escalated 5 pet from its base price in 
1984. 

Payroll overhead is based on 57 pet and 
30 pet of the cost of labor and super- 
vision, respectively. It includes all 
benefits except workman's compensation 
and black lung benefits, which are cov- 
ered by company insurance. 

CASH FLOW ANALYSIS 

The cash flow analysis shown in table 
A-10 lists the accounting entries and how 
they were used to arrive at annual net 
cash flows. 

The annual cubic feet of gas available 
for sale is the difference between total 
gas recovered and that consumed by the 
compressor. 

Revenue is the product of gas sales and 
price per thousand cubic feet. 

Operating costs, which include depre- 
ciation, are described in the previous 
section. 

Development and indirect capital costs 
are intangible costs that are not depre- 
ciable; they are carried forward as nega- 
tive income and deducted against revenue 
until they are expended. 

Depletion is based on the allowable 
rate of 15 pct/yr on revenue with a limit 
of 50 pet of gross income. 

Investment tax credit of 10 pet was 
taken on the direct cost tangible items 
shown in table A-l. The first credit was 
taken in 1986 on direct capital costs in- 
curred in 1984. The credit in 1987 is 
the sum of the credit carried forward 
from the 3 previous years and the credit 
allowed on direct capital for 1987. 

Net income is the sum of after-tax rev- 
enue and investment tax credit. 

Depreciation and depletion are non- 
cash deductions for tax purposes. 



10 



Subsequently, depreciation, depletion, 
and losses carried forward were added to 
net income to determine operating cash 
flow. 

SUMMARY OF DISCOUNTED CASH FLOW 

The summary of discounted cash flow 
shown in table A-ll shows how the net 



present value and discounted cash flow 
rate of return were determined. 

The net cash flows from table A- 10 were 
discounted by using continuous interest 
factors of 25 and 30 pet. Subsequently, 
the discounted cash flow rate of return 
was calculated by interpolating between 
25 and 30 pet. 



CONCLUSIONS 



Results from the economic evaluation of 
drilling horizontal boreholes in an un- 
derground coalbed in Alabama for the re- 
covery and sale of methane gas indicate 
that an investment rate of return of 
25.08 pet could be achieved by selling 
the gas at a relatively low constant 
price of $2.25/Mft 3 for the 6-yr period 
1985-90. 



Based on projections from the American 
Gas Association TERA-Fall 1983 Base Case 
of average wellhead nominal prices in- 
cluding severance and gathering taxes, 
the price of natural gas per thousand 
cubic feet will be $3.96 in 1985, falling 
to $3.60 in 1987 and increasing to $4.28 
in 1990 (11). 



REFERENCES 



1. Brezovec, D. Mine Fans Deliver 
High Pressures. Coal Age, June 1980, 
pp. 84-97. 

2. Campoli, A. A., J. Cervik, and 
S. J. Schatzel. Control of Longwall Gob 
Gas With Cross-Measure Boreholes (Upper 
Kit tanning Coalbed). BuMines RI 8841, 
1983, 17 pp. 

3. Cervik, J., H. H. Fields, and G. N. 
Aul. Rotary Drilling Holes in Coalbeds 
for Degasif ication. BuMines RI 8097, 

1975, 21 pp. 

4. Diamond, W. P. , and J. R. Levine. 
Direct Method Determination of the Gas 
Content of Coal: Procedures and Results. 
BuMines RI 8515, 1981, 36 pp. 

5. Fields, H. H. , J. Cervik, and T. W. 
Goodman. Degasif ication and Production 
of Natural Gas From an Air Shaft in the 
Pittsburgh Coalbed. BuMines RI 8173, 

1976, 23 pp. 

6. Fields, H. H. , J. H. Perry, and 
M. Deul. Commercial-Quality Gas From a 
Multipurpose Borehole Located in the 
Pittsburgh Coalbed. BuMines RI 8025, 
1975, 14 pp. 



7. Finf inger, G. L. , and J. Cervik. 
Review of Horizontal Drilling Technology 
for Methane Drainage From U.S. Coalbeds. 
BuMines IC 8829, 1980, 20 pp. 

8. Harris, G. J., R. W. Dalzell, and 
J. W. Stevenson. Mine Ventilation Prin- 
ciples. Sec. in SME Mining Engineering 
Handbook, v. 1, ed. by A. B. Cummins and 
I. A. Given. Soc. Min. Eng. AIME, 1973, 
pp. 16-22. 

9. Perry, J. H. , L. J. Prosser, Jr., 
and J. Cervik. Degasif ication of the 
Mary Lee Coalbed, Brookwood, Ala. Bu- 
Mines RI 8669, 1982, 13 pp. 

10. Prosser, L. J. , Jr. , G. L. Finfin- 
ger, and J. Cervik. Methane Drainage 
Study Using an Underground Pipeline, 
Marianna Mine 58. BuMines RI 8577, 1981, 
29 pp. 

11. American Gas Association. AGA- 
TERA Fall 1983 Base Case Analysis, Sup- 
plement C. Arlington, VA, Nov. 1983, 
p. 5. 



11 



APPENDIX. —COST AND ANALYSIS TABLES 

TABLE A-l. - Estimated initial capital investment 

Item 

Development: 

Preparation of drilling plan and procedure 

Training of personnel in drilling and maintenance techniques 

Site preparation for surface building and equipment 

Supervision, office, and general overhead associated with development 

Subtotal 

Direct cost: 

Surface building and equipment: 

Building - 400-f t 2 , metal, insulated, complete with utilities 

Gas analyzer and recorder 

Gas flow meter 

Temperature meter 

Flame arrestors - 1 horizontal, 1 vertical 

Compressor - 168-hp, 2-MMf t 3 /d-capacity , 30-psig-discharge 

Check valve - 10-in 

Steel pipe - 2,000-ft, 10-in-OD, installed in shaft 

Fence - 8-ft chain link, 800-ft-long, 12-ft gate 

Miscellaneous pipe and fittings 

Subtotal 

Drilling equipment: 

Electrohydraulic drill and power unit 

Pump - water-recirculating, 30-hp 

Pump - grout 

Mixer - grout 

Pipe fusion machine 

Drill string - see table A- 3 

Subtotal 

Gas collection system - see table A-4 

Gas transmission system - see table A-5 

Gas sensing system - see table A-6 

Total direct cost 

Indirect cost: 

Administration and overhead (except development) 

Contingency 

Total indirect cost 

Net initial investment 

Working capital 

Total initial investment 



Cost, 1984 



$20,000 
3,750 
2,000 
2,580 



28,330 



26,000 

3,900 

2,000 

580 

4,570 

93,200 
630 

72,840 
3,160 
2,470 



209,350 



91,580 

6,870 

3,200 

4,410 

11,730 

69,000 



186,790 



38,000 
295,090 
276,930 



1,006,160 



100,620 
170,270 



270,890 



1,305,380 
193,260 



1,498,640 



TABLE A-2. - Estimated deferred capital investment 



Item 


Cost 




1985 


1986 


1987 


1988 


Direct cost: 

Drilling equipment, drill string bit inserts only, 
table A-3 


$6,550 

38,540 

113,250 

73,210 


$6,000 

28,390 

114,080 

68,030 


$4,350 
21,640 
50,440 
26,460 


$4,260 

6,340 

11,840 

11,280 






231,550 


216,500 


102,890 


33,720 


Indirect cost: 


23,160 
38,210 


21,650 
35,720 


10,290 
16,980 


3,370 




5,560 




61,370 


57,370 


27,270 


8,930 








292,920 


273,870 


130,160 


42,650 



12 



bo 

c 






w 

CO 

< 



co 4_> 

*J CO 

o o 

H o 



o o o o 

CMn oo c 

1/1 iD 1/1 \C 



ON — 1 

CM 
■C0- 



O — I 



o 
f- 
o 

CO 

m 



o ft ft a 

no < < <; 

cm z z z 

<r 



ft 

< 
z 



vo a a o. 

CO <e < < 

z z z 



a 
< 
z 



o ft ft ft 
in < < <c 
en z z z 

-3" 
</> 



< 
z 



en a a a 

cn <c < < 

z z z 



p. 

< 
z 



o a 
o < 

o^z 

nO 
•CO- 



a a 

< < 
z z 



< 
z 



r^ ft ft ft 

m <£, <j < 

Z Z Z 



ft 
< 

z 



o a 

UO Z 

NO 
■C0- 



a ex 
< < 
z z 



< 
z 



\C ft ft (X 

no < <! <3 

Z Z Z 



a 

z 



o o o o 
ro m co o 

•* vD lA \D 



CO — ' 



O — ' 



o 
o 
m 

CO 



o o o m 

ON -H CM 



O 
O 

m 



coo 

—i CO CO 

moo 



a a a 
< < < 
z z z 



a a a 
< < <: 
z z z 



a a & 
< <c <j 
z z z 



ft ft P-, 
< < < 

z z z 



ft ft ft 
< < < 

z z z 



a a a, 
< < < 

z z z 



ft ft ft 
< <3 < 
Z Z Z 



ft ft ft 

< <; <! 

z z z 



o o o 

^H OC 00 

m o o 

m sr «* 



o o m 

CM — H 



CO 



0) CO 

n x: 

•H •> CJ 

co qj co 

n a) 

• iH 
O" CD 4J 

• HH 

z • 

CO 



CO CQ 

co m • 

M CO -orH 

CD OJ rH CO QJ 

U N r-t 13 QJ 

O t-l O O *J 

4j i— i o u co 

CJ CO 

<y (J rH 1— I CO 



I 

c 

•H 
CO 
4J 
CO 

•> cj 

CD CO 

N QJ 

•H 

CO J-J 



0) 
QJ N 
N iH 
•H CD 
CO 



o-o 

CO 



o- 

PQ 



o- 



PQ C_) CJ) Q Q 



-O QJ 

O 4H 

P CD 

rH CO 

rH CD 

•H QJ 

r4 rH 

a 



QJ QJ 

> > rH 

H tH CO 

CO 3 4H 

> CO O 



J* M 

CJ QJ 

OJ 4J 

J= co 

CJ 3 



E 
QJ 
4-1 
CD 
S^ 
CD 

b 
o 



o 

cj 

co 
CO 
bO 

QJ 
B 

CO 

.c 

4H 

QJ 
g 



Ed 

rJ 
PQ 
< 



ft 







O 


o o 


O 


O O 




o o 


o 


o o 


O 


rH 


vO 


co r^ 


CM 


r» cm 




rH 00 


in 


no in 


r-H 


CO 4-1 


co 


<r m 


— — 


cn oo 




<r cn 


h>. 


in co 


On 


4H CO 


* 


— ^ 


*• 


«> ^ 




r 


^ 


•* •> 


n 


O O 


vD 


— i co 


. — i 


O 00 




#-H 


CM 


rH . 1 


CM 


H o 


- — i 


<- 




cn 








— h CM 


CO 






o 


o o 


O 


o o 




o o 


o 


c o 


o 




4-1 


co 




00 










no oo 


<r 




CO 


vO 




^-f 










oo <r 


CO 




O 


» 














m n 


M 




CJ 


Osl 

■CO- 














CM CO 


NO 


co 
co 






















s-» 




















o> 


JJ 






4-1 














" H 


•H 

4-J 






14H 
















c 


CM 


o o 


O 


o o 




o o 


o 


ft ft 


ft 




CO 


i — 1 




CM 










< < 


< 




3 






rH 










z z 


Z 




O" 
























o 


o o 


o 


o o 




o o 


o 


c o 


o 




4-1 


co 


o o 


00 


r* -<r 




NO a 


in 


-h CO 


<r 




CO 


^D 


00 -3- 


^ 


On -* 




CM 


si- 


CM O- 


NO 




o 


• 


* *. 




r r 








^ r 


r 




CJ 


CM 


^O rH 




<T rH 








00 CO 


rH 


1^ 

00 




■a> 














^ 


CM 


>i 




















On 


4-1 






4-J 














— ' 


■H 

4-J 






•4-1 
















B 


ro 


o o 


o 


o o 




o o 


O 


ft ft 


ft 




CO 


i — i 


^-H i—4 


cn 


-H CM 




^^ r- H 


CO 


< <d 


< 




£ 






rH 










z z 


z 






o 


o o 


o 


o o 




o o 


o 


o o 


o 




4-1 


r~) 


CM r-» 


-3- 


-3" oo 




On On 


ON 


in <r 


ON 




CD 


vO 


00 r^ 


CM 


<r oo 




CM 


in 


l~~ NO 


CO 




O 


r 


•» ^ 




*■ *■ 








r w. 


n 




CJ 


cn 

■CO- 


00 rH 




SO rH 








co <r 

CM 


00 
CM 


00 






















rS 




















ON 


4-1 






4-1 














■"■* 


•H 

4H 






l*H 
















c 


ON 


-d- sr 


o 


-J- 00 




<f -J" 


CM 


ft ft 


ft 




CO 


1 — 1 


rH i 1 


On 


-H CM 




— ^^ 


<r 


< < 


< 




3 






i-H 










z z 


z 




o- 
























o 


o o 


o 


o o 




o o 


O 


o o 


o 




4H 


v£> 


00 CM 


NO 


in r^ 




cn cn 


vO 


NO 00 


<r 




CO 


ON 


On \D 


CN 


in r^ 




-H -<f 


oo 


in on 


in 




o 


r 


«l *N 




* *- 








* * 


n 




CJ 


CO 
■CO- 


CM CM 




On cm 








co <r 

CO 


00 

co 


m 










































CO 


>N 




















on 


4H 






4-1 














^ 


•H 
4H 






14H 
















c 


CM 


CM CM 


O 


cm <r 




CM CM 


NO 


ft o. 


ft 




CO 


CM 


CM CM 


CM 


cn <r 




CM CM 


NO 


< < 


< 




3 






CM 










z z 


Z 




o- 
























o 


o o 


O 


o o 




o o 


O 


o o 


o 




4H 


— * 


00 00 


v© 


rH cn 




cn cn 


m 


00 CM 


o 




CO 


On 


oo n 


CM 


<!■ r>. 




rH <J- 


00 


— i 00 


o 




o 


r 


^ *> 




^ •* 








*■ r 


•* 




CJ 


cn 
•co- 


CM CM 




On CM 








co <r 


00 

CO 


<)• 






















CO 


r^ 




















ON 


4H 






4-J 














r^ 


•r-l 
4J 






<4H 
















c 


rn 


co cn 


O 


cn no 




cn cn 


ON 


ft ft 


ft 




CO 


CM 


CM CM 


cn 


CM -3" 




CM CM 


vO 


< < 


<c 




3 






CM 










z z 


z 




C 


































| '. . \ '. 
CD • • • • 
















OJ . . . . 
















rH • • • • 
















a. . • . . 
















CL • • • . 
















•iH • • • • 
















c . . . . 
















T3 • • • • 




QJ 












B • •— 


e 


ft 




c 




• • 


• • •• 


CO • • 4J • 


OJ 


•H 




•H 


CJ • 


s~\ 


• • /—* 


• • CD 


4J 


ft 




1 


iH • 


r^ 


• • i— t 


> • • O U 


rH 


TJ 




CM •• 


4H • 


CU 


. . Q) 


CD . . CJ CD 




B 


• M 


^-^ 


CO ^ 


QJ 


. . QJ 


QJ • rH O 




CO 


• QJ 


« >-i 


B co 


4-1 


C C 4J 


QJ • CO c u 




-J 


• 4-1 


r-i r-i 


3 3 


CO 


•H -H CD 


4-1 • 4-1 O 




CO 


ft QJ 


QJ CO 


OJ C 


N^ 


1 1 w 


• O iH rH 






co E 


QJ XI 


C CO 




cm cm y 


•> • 4-> 4-1 CO 




M 


U 


4J ^^ 


ft E 


CO 


CD 


CD • X> CO 4-1 




C 


_l iH 


CO 




r4 


O O bO 


3 • 3 rH O 




•H 


M 


CD 


C C 


QJ 


4J 4-1 C 


O 4-1 CD rH H 




4-J 


>H 3 


~ QJ 


•H tH 


CJ 


r 1 


£) O CO 




9 


QJ 4H 


QJ > 


1 1 


3 


1 1 4J 


rH rH 4-1 




o 


JJ C 


ft ^ 


CM CM 


TD 


-3- vO 4J 


Cd CO 




M 


CO QJ 


iH CO 




QJ 


•H 


C 






CJ 


s > 


Cm > 




ad 


Cb 




rH 





QJ 



•o 



CO 

3 

o 

iH 

> 

u 
a 

co 

OJ 
rH 

o 

SI 

60 

c 

IH 

o 

3 

O 

rJ 
ft 

c 
o 

c 

E 

o 
u 



T3 
QJ 
M 
QJ 
> 
O 
CJ 
QJ 
U 



c 

CO 

3 
o- 

c 
co 

T5 
QJ 
CD 

CO 

X. 
cj 

r4 

3 
ft 



C 
CO 
3 
XT 

Uh 

O 



-Q CO 

CO O 

CJ CJ 

iH 

rH C 

ft O 

ft tH 

CO 4H 

CO 



re 



CO 

ft c 
< M 

z- 











o o 


o o o o o o o 


c 


> O O 


o 




o o 


O 










m o 


en m CN O ON CM>. 


c 


n m >* 


ON 




ON i—l 


o 






iH 4-> 




—4 00 


— i «tf en sr -h cn 


O 


N H N 


cn 




CN >* 


IN 






cO co 




A 


•» 


n 


t* *•> 






A MA 


A 




•^ a 


A 






U O 




V© O 


in n. en 




1/ 


1 OvO 


sO 




CN CN 


<r 






o o 




vn CN 


CN 








■1 f-H 


•—1 




cn m 


CO 






H 




cn -h 








1/ 


1 






m 


in 










<o- 
































o o 


O O O O O O O 


c 


5 O O 


o 




o o 


O 








4-1 




co- 






sO 




^ 


3 O 






vO 00 


<r 








CO 
















SO 






SO r-H 


00 








O 






















M 


n 








cj 
























rH 
rH 


• 

•o 




00 




























CU 
































00 


>% 


























!-H 




o\ 


4-1 


























rH 




•^ 


•H 


























•H 






•Ul 




o o 


o o 


c 


Ju -* O 


a 




a a 


Cu 


M 






3 














<3 


4 


< 




< < 


< 


■o 






CO 














2 




z 




z z 


z 








3- 


























5*. 
CO 

3 










o o 


o o o o o o o 


C 


> o o 


o 




o o 


o 






■u 




vO 




en 


m 


m 


o 


■\ 






on m 


-* 


O 






co 




-3- 




o 


-3- 




o 


N 






ON -<t 


-3- 


•H 






O 




ft 




A 








A 






a * 


n 


> 






CJ 




o 




cn 






< 


1 
r 






cn vo 


o 
m 


cu 




in 

00 






<n- 






















a 


































on 


>% 




4-1 






















CO 




^H 


4J 
•H 




4-1 






















cu 

rH 






•U 




o o 


-H O O O O ~: 


c 


*. o o 


a 




a. cu 


a 


o 






c 




o 




<■ 






< 


4 


< 




< < 


< 


A 


a 




cO 




•— 1 










2 




2: 




z z 


z 




cu 




3 




* 






















00 


u 




o- 




00 






















c 


CO 






























•H 

o 








o o 


o o o o o o o 


C 


> o o 


o 




o o 


o 


CO 








in in 


on in in 


oo 


c 


1 CN 


es 




m cn 


00 


3 






4-1 




ON v© 


en <■ oo 




-a 


CN 


CN 




vO sf 


o 


13 


a 




CO 




* 




•» 








a a 


M 




A *K 


A 


o 


o 




o 




sf in 


v£> 






c 


> CN 


CN 




CM H 


-a- 


u 


•H 




CJ) 




00 










c 


> 






O rH 


1^ 


Cu 


CO 








<o- 










»— 


< 






rH 


rH 


C 


CO 


00 




























o 


•H 




























3 


s 


on 






4J 4-1 






















CO 


rH 


>s 




<4H 4-1 




















a 


c 




4-1 


























o 


cd 




•H 




o o 


<r m 'O o o o >"< 


c 


k. -tf O 


(X 




a- a. 


Cu 


M 


u 




4-1 




o o 


ON 


i— < 




< 


i 


< 




< <3 


< 


<U 


4J 




c 




00 o 








2 




2! 




z z 


z 








cO 




A 


* 




















T3 


CO 




3 




00 -h 




















cu 


c8 




C 




•— < 






















M 


bO 






























CU 






































o o 


Q Q i, Q Q OOO 


C 


> _o o 


o 




O o 


o 


> 


(V 








cn en 


m -h -^ cm cn o 


C 


) CN 


CN 




cn cn 


in 


O 


C 




■u 




m vo 


SO m O -H i—( CN 


a 


) vO 


vO 




Vf 00 


CM 


CJ 


CO 




co 




•* 




•» 


* 






*N * 


A 




A M 


n 


0) 


J3 




o 




in n. 


vO 


-H 




<r 


> CN 


CN 




NO VO 


cn 


in 


4J 




CJ 




00 










c 


> 






O 


-^ 




M 








<o- 










f— 


< 






<—* 


rH 


>, 


a 


m 

00 




























4-1 






























•H 


i 


ON 






4-1 4-1 




















4-1 




— H 


>> 




<4-l <4- 


1 




















3 


• 




4-1 


























cO 


m 




tH 




O O 


p-» vo r* cn cn o m 


c 


l, mo 


a 




a, a. 


Cu 


3 


i 




4-1 




o o 


O 


CN 




< 




<u 




<: <: 


<! 


cr 


<3 




c 




-* -H 


-h 






2 




2: 




z z 


z 








CO 




A 


* 




















-o 


w 




3 




-H r- 1 




















c 


J 




o 




CN 






















CO 


PQ 
< 






































o o 


O O O O OOO 


C 


> o o 


o 




o o 


o 


T3 


H 








on o 


no in cn oo in on «* 


c^ 


i -h <r 


m 




IN CM 


ON 


CU 






4-1 




-h in 


O >* ON CN 


v£ 


) IN CSJ 


ON 




in m 


o 


CO 






CO 




* 




•» 








* A * 


a 




#N M 


ft 


cO 






o 




en m 


-H V© 




r* 


<r vo 


o 




00 vO 


in 


JS 






CJ 




<r o 

— i •— t 


1— 1 








i 
i 


1—1 




IN ^H 

CM 


ON 

CM 


CJ 




<r 






<o- 






















3 




oo 


























































Cu 




o> 






4-1 4- 


1 
























^H 


4-1 




<4H 4- 


1 




















4-1 






•H 




O O 


-3- -* o m N CM H 


C 


14 ON -* 


o. 




Cu Cu 


Cu 


•H 






4J 




o o 


ON 00 CN 




< 




<u 




<: < 


< 


4-1 






c 




IN 00 


i—4 






2 




2 




z z 


z 


C 






cfl 




A 






















CO 






3 




00 sO 




















3 






o- 




cn -h 




















cr 


























• • • 


UH 
























» • • • 1 


rH • • 


• o 
























• • • >% 


01 • 


cu 












i •• 












. . . . j- 


0) — 


<-* 4-1 












> CO 












> . . . 4-1 


4-14-1 • 


-o co 












• u 












> . . . CU 


co co • 


CO o 












' 0) 










. C (3 ' 


HH . >, 


O 4-» 


CJ CJ 












> -H 










> C -H -H < 


. CO CO . r-l 


"O O CO 


•H 






•• 






• a. 










« "H 1 1 r- 


3 3 rH O 


c o 


rH 3 




a 


0) 






• 3 










> 1 ON vO (1 


1 C C CO CX, 


cO C O 


Cu O 




<y 


C 






' o 










• .. v£) 4- 


1 cO CO -U 


o 


Cu tH 




4J 


<D 






• CJ 










C0 o c 


a a o rH 


CU -H rH 


CO 4-1 




M 


-H 
















S-l O 4-1 •• 4- 


4-> CO 


C 4-1 CO 


CO 






>. 


c r 


CU 


3 1 


C 1 


OJ 4-1 CO X. 


co C 3 43 4-i 


CU CO 4.) 


4-1 <^ 






J3 


•• iH T- 


1 bo i-l f 


• • -H T- 


O 1 s s 

3 1 O O V. 


CU iH -H 3 O 


<-i <-t o 


O rH 






4-1 


0) 1 1 


c 


1 1 


C0 1 1 


•• > 1 1 w H 


rH H 


Z CO 






OJ 


avox 


) cO 


vo a 


1 (U vO CC 


> T3 00 — i J3 


i— 1 i— 1 sO 00 


CO 


4-1 






^ 


iH 


!-| 




cu 


<U i-l 


CU CO 


4J 


CO 






rH 


Ph 


fK 




H 


OS W 


CU > 


CO 


Cu C 






O 












4-1 


C 


<: m 








a< 




















CO 






M 




z- 



13 



14 









CO O O O O 


o o 


o 


o o o 


o o 


3 


O 






































i— 1 


— i nO O O ON 


vo r*. 


CO 


as oo ^j 


ON ON 


00 


i — i 






















CO -u 


r-» no o O cn 


nO en 


O 


NO LO — 1 


CO <f 


CO 


a\ 






















J-l CO 


A * A 


a n 


A A 


^ 


M 




» p. 


•* 


*- 






















o o 


no ri. o no co 


LO — 1 


r-. 


LO 




vO CM 


CO 


CO 






















H cj 


— i r-. co O cm 


lo r— 


C-J 


—4 




t— < — i 


CM 


CO 














CU 


o o o o o c 


5 1 






—4 r* 




CO 


<r 










<t 














W) 


<o- r^ -^ on O r~ 


- CU 






<y> 






























CO 

> 

rH 


i — r-^ lo co lc 
co r^. cn cm a 


N T3 








o o o o o 


o o 


o 


o o o 


o o 


O 


O 


3 CU 






4J 


<o- 




NO 


^o 






CM 


CN| 


oo 














CO 




—I CO CO C 


5 rH 






CO 






u-1 


CO 






I-- 


r^ 


CM 














CO 








4 X 






o 






ON 


ON 






•^ 


. — i 


—H 






























o o o o o c 


n bO 




CO 




















~* 
















o 


<o- 00 CO CO O < 


r 3 






































-3* ON ON 1 — C 


N CO 




00 


>% 






















• 












ON 












ON 


4J 






















•o 












ON 


<r on o r-~ c 


1 3 




i — i 


•H 






















cu 












r^i 




-H NO CO CN 


i r-> 






J-l 


o o o o c 


cx a. 


CX 


o o c 


CX cx 


a 


CX 




rH 






o o o 


O 














-_ 


4 






C 






<c < 
z z 


z 






< < 
z z 


< 
z 


< 

z 




, — 1 






CO O vO 
CO nO CN 


o-l 






















CO 












•H 














o o o o o c 


5 • 






3 






















M 




rH 


A 


A A 


* 










NO NO 00 ON CN - 


* >N 






O" 






















T3 




CO 
(J 


LO ON CO 
O CO ON 


00 
m 








ON 

00 


On <r —i LO CO Lf 


N rH 


















































o o o o c 


o o 


o 


o o o 


o o 


o 


o 




>N 




o 


!<1 N H 


CM 








ON 


CO CO 00 CM CO P 


> O 






4-1 


O CM CN 


<r no 


o 


00 vO -H 


CO — i 


NO 


vjO 




rH 




H 


A 




M 








1 — 1 


<r <o- CN CN ON c 


) 






CO 


o o m 


LO O 


vD 


CO 




<r <r 


00 


sr 




CO 






1— 1 




CM 






— 




<o- 




H C 


■) CO 






o 

U 






















3 
O 
•H 






</> 










3 
O 
•H 
















NO <J" LO 


to oo 


en 


! 




. . 


CM 


NO 

CM 




















o o o o o c 
nO oo co cm oo r> 


) CO 

■ o 






</> 






CN 














cx o a 


o 










r^ 
























> 






<3 m < 


CO 






4-1 


CO 


On CO lo <r ---J- O 


N CJ 


























CO 


>. 










4-1 












CU 




CO 


Z vO Z 


X> 






CO 


CO 












on 


4-1 










CM 












u 




CO 




A 


* 






•H 


ON 


CO CN NO 00 CN f 


> rH 




■ — i 


•H 






















cx 




<3N 


CM 


CN 






CJ 


rH 


<j- <r cn — i on cn 


i CO 






4-1 


o on o co c 


a, a. 


cx 


o lo a 


cx cx 


CX 


CX 








1 — 1 


<r 


~<r 






CU 




</> 


-i cr 


N 4-1 






C 


~H 




< < 


< 


O o <! 


z z 


< 


< 

z 




CO 






l-/v 








M 










■-al 






CO 






z z 


z 


-i<r z 


z 




cu 


>-, 














a 




o o o o o c 


> CX 
















3 










•» 












rH 


u 




cx o a 


o 






CU 




pn« p^ cn O r^. c 


N CO • 






o- 










oo 












o 


« 




<C no < 


^3 






•3 


r* 


on lo p^ o <t r> 


- o -a 




























x: 


a 
a 


[-^ 


r?1 , i r^. 










00 
ON 








4_| 4_| 








o o o o o 


o o 


o 


o o o 


o o 


o 


o 




00 




A 


» 






rH 


co — i o <r <r -a 


e 






— i sr oo r> 


O CM 


CN 


N CM N 


-H O 


r—t 


CO 




M 


3 


CT\ 


o 


o 






CO 


1 — 1 


<r <r cm o oo o 


N CJ CO 


cu 




4J 


— " en <t CO 


00 CN 


o 


-^ -H 


co r-~ 


o 


o 




C 


CO 


^H 


CO 


CO 






3 




</> 




4 CN 


1 CU -H 


4-1 




CO 






















•H 
O 














3 










M CJ 


CO 




o 


CO -h lo nO 


vO co 


Cx! 


CO 




CO CM 


NO 


oo 




4-1 




co- 






CU 




o o o o o c 


> -H 0) 


>, 




CJ 


~H —4 f— 




<f r-4 


k -C» 










NO 




3 
T3 


c 
(1) 












rH 

3 




no r^ -<r — i o a 

O O r-i ON on C 


) T3 M 
> CX 


03 




<o- 






















cx o a, 


o 




NO 




^O 
























O 


a 




<s<; 


r-- 




■o 




CO 
































bO 


CO 












4-1 












u 


4-1 


nD 


Z 00 z 


CO 




cu 




ON 


no cn <r -h — " nc 


> CU T3 


G 


ON 


>N 










CM 












cx 


CO 


00 




A 


A 




x: 




-1 


•J 4 H CO Ml" 


\ u 


•H 


i — i 


4J 






















B 


cu 


On 


CO 


CO 




CJ 






<o- 




CN 


1 M 4-1 


CO 




•h 


en on o on c 


o, CX 


cx 


o o a 

O ON <U 


CX cx 

< < 


CX 

< 


cx 
< 




o 

c 


> 
C 


i-H 


p^ 


r^ 




CO 












CU o 


s 




4J 


CN 




< < 


< 






CM 


CM 








o o o o o c 


) cm C 


cu 




C 






z z 


z 


oo on z 


z z 


z 


z 






•H 




<J> 






3 






o cm o no <r cs 


1 V 


CO 




CO 






















a 
o 














o 

•H 




CO 


^^ p~\ r^^ >-vi in r^ 


< 13 <U 






3 










ON 












rH 




cx o a 


o 






CO 








CO 

CO 




CO 










*-H 












u 

cm 


cO 

4-1 


m 


<! CN < 
Z ON z 


CN| 

ON 




4-1 

CO 




On 


-i 00 CO <■ — < c 
co cm <r <r lt 


CO 
1 T3 
































bO 






o o o o c 


o o 


o 


o o o 


o o 


o 


o 






•H 


CO 




A 


•V 




•H 






<j> 






1 3 rH 






4-1 


O O O CN 


cm en 
r-. on 


LO 


P^ CM CO 

CO — i 


cn <r 

LO O 


NO 
CO 


IN 




•3 
CU 


CX 

CO 


ON 

1 — 1 


<N 
ON 


CM 

ON 




CJ 

cu 












CO co 


CU 














• 4-1 


c 




CO 


* A 


A A 


a a 


•> 


^ 




#» A 


*• 


a 




M 


CJ 




IN 


CM 




u 














> rH 1-1 


CO 




o 


-H ~1 \Q SO 


LO — 1 


r>> 


CO 




CO CM 


LO 


CO 




CU 






CO- 






cx 














Cfl CX 


4-1 




c_> 


CN] — 1 >— < 


CO -h 


NO 










r-. 




> 

o 


-o 

cu 












cu 

Q 














•H CO 
4J O 




</> 


















CO CX O 


O 
















cu 

a 


CO 
























CJ 

cu 


4-1 

CO 




00 < v£> 
CO Z CM 


nO 


















•H 
3 bO 


CO 












4-1 
















1 
















ON 


>n 










CM 












u 


a 


<r 


A 


A 


^ 


















•H 3 


i 


—1 


4-1 
























•H 


CO 


CO 


CO 


CO 




• 




CM 








•H 






■H 


O O O O CN 


cx cx 


cx 


o lo a 


CX CX 


CX 


cx 




>> 


4-1 


ON 


O 


ON 


ON 




oo 




1 








CM _-i 


• 




4-1 


<r -h -h 


<J <- 


<: 


ON < 


<c < 


< 


< 




4-1 


CO 


i — i 


co 


—4 


<r 




I 




< 








O r4 


vO 




c 






z z 


z 


LO — 1 Z 


z z 


z 


z 




•H 


W 




A 




» 




< 












O 


1 




CO 










*» 


^ 










4-1 






~H 




r— i 








-a 








B 3 


<c 




3 

cx 










CM - 
CM 












c 

CO 

3 


1 




</> 








33 




c 

CO 








CO T3 

3 


a 


























. 












































j 






o o o o o 


o o 


o 


o o o 


o o 


o 


o 




cr 


r^- 












<J 




r-i 








II CO 


pq 






o o o o o 


o o 


o 


P^ 00 nO 


-h CM 


co 


CO 






1 












H 




1 










< 




4J 


O v© o o o 


NO NO 


CN) 


r~ cm 


. — i nO 


r^v 


ION 




T3 


<d 
















< 








<U « 


H 




CO 










^ 




A A 


^ 


A 




c 


























bO CO 






o 


vO CO O On CN 


r-» cO 


<r 


r^ 




oo <r 


CM 


cO 




CO 


Ed 
















cu 








CO 4-1 






CJ 


I — co co no — i 


en cm 


NO 








. — i 


p~ 






►J 




4-1 < 












rH i 








> CO 








</> 




CN 


CM 










CM 




-o 


« 




3 . 












rO . 








-H O 




St 

CO 
























CU 
CO 


H 




CJ 

a 4- 


• 




cu 






CO < 

4-1 ' 




ir 
1 


• « 


CO CJ 
























CO 




ON 












4-1 












CO 






4-1 C 






lH 








sr < 




rH 




*— 1 


4-1 










CM 












j3 
CJ 




e 


co a 

CU E 


• 
• 




XI 
CO 




a 


4-1 • 


I 

< 01 




+ CO 
4-1 






■H 


N \0 -n vO <t 


CX cx 


a 


O co CX 


cx a 


CX 


cx 




M 




cu 


> 4_ 


rH • 


CJ 




CU 


3 f 


r- 


o • 


3 i-C 






4-1 


co <r <r 


< < 


< 


o r- <; 


< < 


<! 


< 




3 




4-1 


C cr 


CO • 


•H 




4-1 


cu I 


cu x 


1 • 


O CX 






3 


^H 




z z 


z 


lo r-~ z 


z z 


z 


z 




CX 




rH 


•h a 


4-1 • 


rH 




M 


a < 


rH Cfl 


<: • 


•H CO 






CO 










* 


















> 


•H • 


a 






cx 


XI 4-1 




4J O 






3 










LO CN 










>, 






-H C 


CX . 


cx 






-H CU 


CO 


0) • 


CO 






CD- 










CO 












4-J 






CO i-i 


CO rH 


CO 






3 r-l 


4J a rH • 


•H 4J 




























-P-l 






■i^ 


a co 

4-1 








cr x 
cu CO 


a 

A OJ 


o • 


a cj 

0< 0) 




































4-1 






4-1 "0 


4-1 






CO • 




































3 






•H CU 


bO O 


o 






4J 


a 4J 


4-1 • 


u u 




































CO 






C M 


3 H 


z 






-a 


01 CO 




CX -H 




































3 






•H U 


•H 








3 • 


> 4-1 > 


t A • 


cu xi 




































cr 






cu 

4-1 LM 


M 


cx 






CO 4J 

3 


CO CO 


a • 

cu • 


-a 3 

•H 




































CM 






cu cu 


O 


< 






oo cu 


co 3 


4-1 • 


rH 


















4J i 


c 












• 


o 






z a 


3 


z 






3 a 


O 


CO • 


Cfl « 


















C 


1- 


• 






H 


a) 














•H Q 


. 3 -H 


>N • 


3 4-1 


















cu • 


1 






— CO 


rH 


4-1 












T3 -H 


O CO 


CO • 


3 cfl 












CO 


jj E 


~3 






4J -H 


X) 


CO 












rH 3 


•H CO 




3 O 












l-l 


CO cx 3 -~ 






CO U rH 


<0 


o 












•H O 


1 4J -H 


bO • 


CO CJ 




S 






CI 


o 


O T-l tH f 


• 




O CU CO 


CJ 


a 












3 CU 


o a 


3 rH 






<u 




>> 


> c 


CO 


CJ 3 1 






U 4J 4-1 


•H 














XI 


0) CO 


•H CO 


CM 4-1 




4-1 




rH 


c 


co i—i cr <r 




rH CO O 


^H 


c 












tx 


) rH 3 


CO 4-1 


O 3 




l-l 


u a 


•r- 


cu co c cu •• \ cr 


• 


co c a 4J 


a, 


o 












CU 3 


rH Cfl 


3 O 


CU 






o a. . 


4- 


U 4-1 O rH co t- 


• 


4J O 


a 


•H 












O -H 


o u 


0) H 


e a 






• • CO 3 M <X 


Cu o -h rH >, a 


• 


O "H rH -O 


CO 


4-1 












CO rH 


CJ 4-1 


CO 


3 CX 






4-1 3 CO CU 4- 


S 4J 4J Ql •• C •>!— 


• 


4-1 4-1 CO 3 




CO 












CM -H 






CO o 






C 01 4-1 Cf 


OX CO 4-1 rH -H <U C 


M • 


XI CD 4-1 CO 


4J 


rH 












l-l -H 


CO CO 


CO 


— -H 






cu en u 3 


03-Ho<o>cxr 


• 


3 -H O M 


O 


rH 












3 M 


CO CO 


CO 


01 






iu a n 


(*> rH H -H >-, -H C 


CU CO ^ H CJ 


z 


CO 












co a 


o o 


O > 






a. co 3 s 4_ 


U CO l-i r-l Pu CJ 


3 CO 




4J 




















■H CO O O cr. 


•H 4-1 0>O 


rH 4J 




CO 




















3 CO Cu CJ C 


<3 CO 4-1 Oh 


O CO 


CC 


c 




















o- 


C co 


B 


< 


h-4 






















Ed 










h-l 




a 








rH 






z 



































CD 
O 
CJ 

bO 

3 



(0 
u 
CO 

cu 
o 



(0 

3 
3 
CI 
«0 

Xl 
CO 
4-1 

CO 





CO 



ON 

w 









c 


> O 


o o 


o o o o 




o o 


o 


o 






o o o o 


o 


O 










o 


N O 


ON — 1 


O ON vO LTN 




r^ -fr 


-^ 


X) 






















o 






1— 


* CN 


o o 


m <r \o -h 




LO vO 


CN 


CO 






















ON 


















































ON 






e> 


J <f 


-H CN 


r-~ c 




v£> —1 


00 


o 






















.-H 






«— 


* 








^H 


CN 








CO 




























</ 


> 
















































c 


> o 


o o 


o o o o 




o o 


o 


o 






o o o o 


o 


o 










OC 


> CN 


on co 


-J- CN CN ~d- 




00 o 


00 


CN 






X 00 CN X 


CO 


ON 




ON 






c 


> 00 


ON 00 


^O r^ <f — < 




ON LO 


<r 


X 






LO — 1 X CO 


CN 


LO 




00 


















































ON 






F— 


< co 


1— 1 


vo r i--) o 




LO <— t 


r-^ 


r^ 






CO — H O LO 


00 


CO 




^H 
















i-H 


CN 








CN 






-tf <d- oo x 


—t 


00 










</ 


>- 
































^H 




—4 










c 


) o 


o o 


o o o o 




o o 


O 


o 






o o o o 


o 


o 










r~ 


r-^ 


o ^o 


<r> O O O 




CO n£> 


ON 


ON 






r^ -d* O r^ 


r>* 


00 




00 






c 


> vr 


ON vO 


O — h CN CO 




>* co 


r-. 


o 






CIO CI N 


—i 


00 




00 


















































ON 






c 


> CO 


.— I 


O VO ■ 1 03 




LO r-H 


vO 


LO 






CO -H O <t 


00 


CN 




-H 






1— 


1 








^H 


-H 








CN 






-*-* 00 iO 


—1 


00 










<f 


h 
































^H 




-H 










c 


) o 


o o 


o o o o 




o o 


o 


o 






o o o o 


o 


o 










LT 


i vO 


CN -* 


ON <■ -d" 00 




-d- <!■ 


00 


X 






r*» oo r^ cn 


LO 


r^» 




r>« 






1— 


* <— i 


oo m 


•JvOO* 




ON CN 


i-H 


00 






co co co — ■ 


o 


-H 




00 


















































ON 






o 


< CO 


-H 


LO <1- CN vO 




<r —i 


X) 


<N 






N-cf * CO 


<r 


CN 




—4 






</■ 


)- 








^H 


i— 1 








CN 






LO LO O - 




CN 


<!■ 










































-H CN 




CN| 










c 


) o 


o o 


o o o o 




o o 


o 


o 






o o o o 


o 


O 










r> 


r«-. 


vO O 


r^ o on on 




co co 


X 


LO 






CN ON CM CO 


LO 


00 




x 






<d 


00 


rs. <r 


00 LO 00 CO 




LO -H 


X 


o 






LO CN 00 X 


r~» 


co 




00 








* 


* 


m 






M 


*« #» 




A m 




ft 








A 


^ 


#» 


A 


* 


* 




ON 






a 


) CN 


i— t 


cn oo — i m 




Vt -H 


LO 


1—1 






— 1 00 CO CO 


LO 


ON 




^H 






V 


h 








•—< 


r— I 








CN 






X LO — 4 CO 


CN) 


LO 










































— I CN 




CM 










c 


) o 


o o 


o o o o 




o o 


o 


o 






o o o o 


o 


o 










-d 


vO 


o o 


vO O uO uO 




ON LO 


<t 


ON 






X X CN >d- 


<r 


00 




m 






a 


) X 


r-« po 


\D m MN 




— I o 


CN 


vl- 






en h u\ •* 


00 


CN 




00 


















































ON 






r^ 


CN 


-H 


-<f c 




<■ —< 


LO 


ON 






ON X ON LO 


<f 


o 




i-H 






V 


r 








-H 


r-H 








—1 






LO LO O CN 


CN 


LO 










































r^ CN 




CN 










CO 


















































rH 

CU 


















































4J 


















































CO • 


















































s ; 




• a) 

' CO 














































u 




• 3 














































CO 




• O 














































4J 




• X 














































CO 


> 


N 














































3 


X 


In 
CO 














































X> < 


> 4- 


4-1 














































CI - 


> c 


CO 














































CO 


c 


3 














































CO 




"O 














































CO 


» r™ 


a 














































bO 


1 t- 

> c 


CO 

• 














































~ 




•> 
























X 


< 




















4-1 


> a 


XI 














































c 


b 


CO 






• r- 


1 
















V 


" X 


■ 


















CO • 


> c 


CO 






> c 


1 
















4- 


■ — 




















s 


' Ct 


x 




> »*"\ 


> X 


. 


> G 


CO • 








4- 


cr 


< 


















a. 


X 


r-t 




« co 


• ct 


< 


' O 


CD • 








T- 


4- 


< 


















•r-l 


• c 


1 rH 




- >% - 


' 1— 


■ 


' -H 


3 • 








X 


<4- 


< 


















3 




CO 




. co - 






' CO 


o • 








a 


T- 


< 


















a* 


i 


« 3 




. x) 


■ a 


■ 


' -H 


X! • 










X 




















CO X 


i > 

.» r— 


•> 




> CN < 


• c, 
> c 


■ 


• > 

> r-l 


(-1 • 








CN 


V 


1 

X 


« 










e 






T3 Cr 


1- 


M 




> ^^ < 


ct 


' 


CO 


CO • 








> 


CN 


■^ 












cu 






CO 4- 


• ct 


O 






c 




> a. 


4-1 • 






■ • 






y 


« 










•u 






CO »4- 


x 


CO 




> >% 


- a 


< 


3 


CO • 






M 


4- 


> 


4- 


< 




XI • 




M 






x i- 




CO 




> rH < 


4- 


( 


> CD 


s • 






O 


<4- 




14- 


< 














rH X 


a 


CO 




- i-H - 


• C 












X 


•r- 


4- 


i- 


" 




4J 3 








rH cr 


4- 


1-1 




• co 


• T- 


' 


. XI •• 


XI • 




G 


CO 


X 


<4- 


X 






LH O 








0) 


Ct 


& 




« 3 • 


Ct 


< 


« G co 


c • 




o 


rH 


Cf 


1- 


cr 


< 




•H -H 








3 c 


1 c 


e 




• a < 


E 


« 


CO 4J 


CO • 




•H 






- X 








X 4J 










•r- 


o 




> 3 - 






l-l 


CD • 


4-> 


CO 


. — 


cr 


cs 


< 




co co 








M 


r. 


CJ 




. CO < 


X 


< 


sj CO 


~ at • 


cO 


CJ 












i-i 








1-1 4- 


X 








C 




O Cu X> -H • 


M 


G 


1 


i — 


> 




«, 


— ( CO 








O *4- 


= 


o 




' rH ' 


ct 


■ 


X 


CO rH • 


CO 


CO 










4J 


Cu 








co -r- 


I- 


4-1 




« 3 ' 






CO X) 


CO Cu • 


Cu 


C 


c 


1 


4- 


< 


3 


1 o 








co x 








. CO < 


• b 


3 • 


■ rH C 


x a • 


O 


0) 


•r- 




14- 


< 


CO 










CO c/ 


I •• 1 


CO 




• x: « 


C 




CO 


rH 3 • 




4-1 


C 


1- 


•r- 


< 


4-1 


P bO 








M -s 


- 1-1 


u 




• i-i < 


•i— 


« 


CO 


rH CD • 


CO .. 


c 


CC 


a 


X 




CO 


CO G 




• • 


• • 


ax 


o 1- 


•H 




. CO « 


4- 


i 


CJ CO 


CO 


CJ G 


•H 


X 


c 


u cr 


< 


•H 


CO -H 




g 


U 


e 


x c 


cO 




> > ' 


et 


< 


cO CO 


3 co • 


<0 O 


CO 


c 


ri 


■>» 




CO 


3 rH 




o 


o 


O CN 


I CO v 


a. 




• o 


r- 


■ 


14-1 -H 


3 • 


<4H -H 





a 


a 


CN 


■ 


co 


•H rH 




•H 


XI 


O "-s 


. rH cr 


I CO 






a 


. 


l-l rH 


« o • 


r-l 4J 




E 


X 






cO 


bO -H 




4J 


cO 


•— 


< a 


i-i 


4-1 1-1 i— 


c 


u < 


• 3 Cu 


r-l CO rH 3 CO 


x> 






1 


i — 




3 In 




CO 


rH 


CO 


CO J- 




C O ct 


c 


c 


CO Cu 


O 3 co CD l-i 


C 


1 


1 




<x 


G 


CO X3 




M 




CO 1 


o c 


u o 


CO CO 4- 




c 


3 


co co 4-1 0) 


CO 






cr 


4- 


O 






CO 


WJ 


bO 


3 E 


! -H 


a co c 


1— 


•r- 


rH CO 


CO rH O rH CU 




i- 


|J 


r- 


C 


•H 


4-1 rH 




.. Qu 


3 


> 


-, CO C 


X) 


Cu, CO 4- 


ct 


f 


CO 


CO r-l 4J CO O 


bO 


a 


a 


aj 


4- 


CO 


O CO 




4-> O 


•H 


X. r- 


1 3 C 


> o 


•r-l ^ X 


4- 


■1- 


4J CO 


U 0) X 4-1 


C 


i— 


r- 


r- 


X 


•H 


(11 4-1 




CO 


4-1 


CJ T- 


CO 


•rH 


3 Cu Z 


c 


> 


o o 


Cu O 3 O bO 


•H 


l-H 


r- 


c 


s 


> 


•r-l O 




O CO 


CO 


co ct 


1 4J C/ 


) 1-1 


cr S y 


E- 


)- 


H co 


co CO H C 


r^ 


■H 


■H 


X 


<x. 


IH 


O H 




CJ o 


u 


X X 


I 3 ct 


I CO 


CO o 




a 


4-i 


O -H -H 


rH 


r- 


r. 


ct 




CO 


r-l 




CO 


OJ 


CJ 


•h e 


) O-i 


c_> 




c 


U r-l 


OS rH 


■H 


P 


c 


kJ 




Cu 


&4 




4-1 UH 


Cu 




CO 








j 


3 


rH 


l-l 










3 






CJ (-1 


O 




2 








cr 


CO 


•H 


a 










CO 






cu 3 


















M 


















M CO 


















Q 


















•H 




































Q 





















































15 



16 











O 


o 


O 




O 




o 




C 


) o 




o o 


o o 


o o o o 


o 


o 












ON 


nO 


m 








1 — 1 




c 


i <r 






ON 


On r-«. 


— i on o r>» 


r-~ 


m 






O 






CN 


. — 1 


-d- 








m 




a 


) co 






o 


o r*. 


o o - 


4 O 


rH 


rH 






ON 






•* 


r* 


•» 














** <rN 






A 


A • 


n 


M 




m 


m 






ON 






o 


CO 


co 












r- 


« 00 






co 


co r-. 


CO \0 CO r-H 


<t 


CO 






— H 






-H 




rH 












CN 


J CM 










m 


co 


CM —4 


co 


r-~ 












c/> 






























- 1 






rH 


CM 












O 


o 


o 




O 




o 




C 


> o 




o o 


O O 


o o o o 


o 


o 












uo 


r-» 


CN 




LO 




ON 




cr 


1 r~» 




NO O 


vO o 


NO 00 00 CN 


o 


<!• 


• 




ON 






co 


00 


CN 




00 




«tf 




oc 


) —i 




CO CN 


LTl liO 


nO o o o 


rH 


00 


CU 




oo 






•» 


* 


«4 




r. 
































CJ 




ON 






ON 


CN 


CN 




nO 








r~ 


. LO 




<r no 


O — i 


O CO CO o 


co 


vO 


3 




rH 






<y> 




--H 












c* 


J CO 




o 


—i CM 


ON CO CO CO 


vO 


00 


3 
































r-4 


r-H r^ 


<d- 


co 


co 


00 


M 

3 










o 


O 


o 




o 




o 




c 


> O 




O O 


o o 


o o o o 


o 


o 


co 










o 


—4 


rH 




uO 




NO 




c 


i -d- 




NO — < 


r»~ -h 


o r^ — n no 


r~- 


<}■ 


3 




OO 






m 


O 


r— 1 




i— 1 




<r 




a 


> <r 




o —• 


r-H ON 


NO ~* O — l 


H 


CM 


•H 




00 






* 


*» 


A 




r. 




































ON 






00 


CM 


rH 




r~- 








r> 


- m 




CO vO 


ON vO 


O CM CO ON 


CM 


u-l 


So 




r-H 






</> 




"-H 












C> 


J CO 




o 


O co 


O CO CN CN 


UO 


00 


3 
































-H 




4 r^ 


uo 


co 


co 


00 


3 


















































Cl 










o 


O 


O 




O 




o 




c 


> o 




o o 


o o 


o o o o 


o 


o 


a 










r^ 


-h 


00 




CM 




«*■ 




c 


1 ON 




r-» co 


O ON 


ON "*0" CO CO 


NO 


ON 


o 




r^ 






00 


<r 


CNI 




ON 




sr 




a 


) r^ 




nO 00 


UO NO 


nO ON 1 — uo 


CM 


00 


o 




00 






<n 


*» 


n 




r. 




































ON 






r-«. 


CM 


o 




ON 








r> 


- 00 




cm r-» 


O CN 


NO O -CT NO 


rH 


00 


So 




-h 






</> 




rH 












c^ 


I CO 




co 


Sf NO 


-h ^rj- on CM 


CM 


r^. 


rO 




































r-H -H 


vO 


CM 


co 


ON 




XI 
CU 
















































Ti 








O 


O 


O 




o 




o 




c 


> o 




O O 


o o 


o o o o 


o 


o 


3 


3 








ON 


<r 


CO 




CM 




CM 




c 


i r*. 




00 ON 


r>> uo 


UO NO 00 LO 


CO 


<r 


M 


3 


NO 






CM 


CNI 


uO 




ON 




^r 




a 


) —i 




r^. cm 


O —1 


CO -H O O 


rH 


NO 


cu 


•H 


00 






n 


<* 


M 




4* 
































> 


4J 


ON 






r-s 


CM 


ON 




o 








r~ 


- ON 




O 00 


ON CM 


O CO nO CO 


ON 


CN 


O 


3 


1— 1 






</> 








r— I 








CN 


J CO 




<3- 


-n- uo 


CO St UO CN 


r-» 


UO 


CJ 


o 






























-H 


r-H rH 


NO 


CM 


CN 


ON 




o 
1 
















































CU 








o 


O 


o 




o 




o 




c 


> o 




o o 


o o 


o o o o 


o 


O 


M 


1 








m 


r»» 


CN 




<r 




o 




c 


) r^ 




ON 00 


r^ co 


nO 00 CN 00 


o 


<r 


3 


4J 


LO 






r^ 


O 


00 




00 




<r 




a 


) O 




m on 


UO 00 


O <* ON UO 


UO 


o 




CO 


OO 






n 


-. 


M 




* 
































-3 


o 


ON 






nO 


CM 


00 




o 








r~ 


- ON 




uo r*. 


CO UO 


r~» — 


i O CO 


<f 


co 


CJ 


o 


— 4 






</> 








r-H 








CN 


j co 




CO 


-o- o 


NO -3" UO rH 


vO 


r^ 


•H 






































4 —4 


uo 


rH 


rH 


r- 


-3 


bO 
















































5 


s 














































•H 






































. bo 










« 


4-1 












XI 


























■ 3 










bO 


CO 




















^^, 


















• -H 










3 


U 












O 








m 


















» -H 










3 


<U 












<r 








CM 


















» y-t 










-H 


o. 












CM 








• 


















» TH 












o 












X 




3 




CM 


















• M 

• "3 










r^ 

CJ 


r-l 
















































3 


CO 












T3 




o 




X 


















■ X) 










rH 


3 












-^, 




• 






















• 3 










rO 


3 












si 




— I 




u 


















> 3 












C 












• 




1 




rO 




























XI 


CO 












rx 




1 

bO 




X) 


















• cu 

> CJ 










3 
3 


x> 
















3 






















. CO - 












<D 












o 




•H 




CO 


















> UH 










3 


4-1 












o 




-3 




sO 


















• M < 










O 


CO 












o 




H 




CO 


















• 3 ' 










•H 


s 












» 




•H 






















> CO < 










4-1 


•H 












•— 1 




3 




X 




























3 


4-1 
















-o 






















> M < 










CO 


CO 












1 








-a 


















> o a 


« 








3 


1 










M • 


CU 

3 
•H 




4-1 

3 

CU 

a 




KN 
4-J 
CM 


















' CM C 

C 

' XI ct 

' 3 C 


■ 








cu 

o. 

a 
o 


• 










cu . 


-3 




Cu 






















> cu a 


< 








o 


ON 
1 










•H • 

rH • 


CJ 

CO 




•H 

3 




O 

oo 


















- J2 4J 

- M C 


I 








CO 


< 










O. - 


a 




err 
cu 




o 


















CU i- 
> > ct 


< 
< 








"c 


w 


a 








3 • 


3 








<r 


















O E 


■ 








3 


J 


0) 








CO • 


O 




X> 




CO 














(J . 












a 


CO 


4-1 










iH 




3 


















3 < 


-H B 


< 








^ 


<! 


1— 1 








So • 


CO 




cO 




1 














3 < 


3 CU 


< 








M 


H 










rH • 


3 

•4-1 




CO 
4-1 

.3 


>n 


u 

o 

CO 














cu • 
> < 

cu < 

M < 


M 4J 
CU CO 
3 > 

3 CO 


4 

4 
S * 

4 








o 
s 

4-1 












3 • 


M 




bO -3 


CO 
















bO 




3 • 




a, 










3 


CO • 


cu 




•H 




0) 














u-l < 


bl 


} 


CJ « 




3 










CO 


,3 • 


X 




rH 


o 


u 














O « 


Xi 3 


OC 


3 ♦ 




CJ 










•H 


M • 


•H 






vO 


a. 














4J 3 -H 


1 


3 • 




X 










CJ 


CU • 


s 




4-1 


r> 


B 














M CO CO CO 


< 


M • 




cu 






-a 




•H 


> • 






o 


~ 


o 














CJ O 3 




3 • 










a) 




3 


o • 


* 




a, oo 


o 










rH « 


a. cj cu cu 


<D 


CO • 




co 






3 


• • 


-3 




co 




co 














CU i 


o co 


rH 


3 • 




4-1 






C 


a 


CJ 


m • 


Q, 






X 


u 






-— 




3 « 


O 4J -H 


rO 


•H • 




iH 






•H 


<U 


CU 


o • 


a 




CO 




o 






• • 




3 • 


rH CJ 14-1 CO 


3 




rH 


UH 






4J 


4-1 


4-1 


CO • 


3 


JC 


CD 


J3 


HH 






-a 


rH 


o . 


CU >4H Cfl 


4J 


X) • 


3 


3 






c 


CO 




CO • 


Cu 


« 


u 


• 








(0 


<U 


CO • 


M O bl 


) 


3 • 


4-1 


3 






o 


>> 


.. CJ 


CU i— t 




s 


CO 


3 


CO 




rH CU 


C 


M r-t 


• • -H 


1 


CO rH O 


CU 






a 


CO 


CU -H 


M CO 


*» 


^d 




M 


CO 




CO JZ 


c 


cu co 


X T) -O 




Cfl 4J 


-C 










O 3 


a, 4-i 


4-1 




1 


**^ 


bO 


t<-\ 


M M 


o 


a, m 


CO •• 3 


3 


X 4-1 








i 


bO 


3 O 


a o 


•H 


CO 




CO 




4-J 


O CU 


CO 


o 


4J rH U CO 


O 


id o'tj 


rH 








c 


CO M 


O 4J 


3 


«* 


bo^r 


TJ 


CM 


4-1 > 


u 


-o u 


CO CO 


•H 


4-14-13 


rH 






4-1 


•H 


3 4-> 


CJ -O 


3 


o 


3 


O 


CO 




-Q o 


01 


CU XI 


CU 4-1 O CO 


• • 4-1 


-Q 3 


3 






CO 


CO 


CU CJ 


3 




• 


•rH 


• 


0) 


C 


3 


Q 


-•H 3 


CJ O CJ c 


4-1 Ct 


>* 3 M 








o 


c 


4-1 CU 


M C/j 


rH 


o 


4-> 


o 


,-C 


C 


C/J rH 




M C/j 


C b-> o 


CO -H 


4-1 C/j'O 


co 






o 


cu 


3 r-t 


3 


•• rH 


c/> 


j3 


CO- 


rH 


c 


rH 


CU 


CO 


CO 4-1 -H 


O O 


M 


3 








CO 


•H W 


M -H 




bG 




rH 




O 


bl 


JrH 


M CJ 4-1 


cj 3 


CU 


X) 






4-1 




CO 




cu >-> 


X 


■H 


X 


CU 


— 1 


M 


CO 


CO 


CU CU CO 


M 


a. 


3 






CJ 


CO 


2 




* q 




J 




3 




>, 3 


CO 


> MM 


xi a 


. o 


rH 






0) 


cO 






o 












CO 






CU -H CU 


cu cu 


M 


CJ 






M 


CJ 






P-. 












&4 






oo -o a 


. X Q 


CU 


3 






"H 


























3 O 


•H 




M 






Q 




































r-l 


Ch 








— 






CO 
>N 

rH 

CO 

c 
co 

o 



x; 
en 
CO 

o 



I 



O in 
in cn 

CN) • 



o m 

cn CNI 

r-~ • 

» CNI 

in <o- 

oo 

on 

o> 
ro 
in 



O in 
in cni 

* CN 

oo <o- 

o 
in 

oo 
O 



O in 

N© CNI 

in • 

~ CNI 

\© <o- 
rN 

o 

m 
CNI 



O in 

00 CN| 
00 • 

* CN 

<r -co- 
rn 

CN 

n© 

v© 



O in 
cn cn 
cn • 

•> CN 

o\ <o- 

ro 

o 
in 
-fl- 



ex ex 
< < 

Z Z 



O O CX O 
00 — ' <C 

iD !M 2 



rN cn 

in in 

m cn 

i 



o c a o 

r~- r-~ -<1 

^ N 2 



■O- in 

f-t oo 

CN 00 
.. I 

.—4 



o o a o 

<f O < cn 

—i cn Z On 



v© oo 

CO oo 

■> i 

■co- 



co o cx o 

N On < N 
ON 00 2; CM 



v© 00 

cn in 
V© on 



O O CX o 
cn <r < r»- 
in v© z cn 



— I CN 

cn m 
m on 

r. I 

■co- 



CD O Q. O 
m <r < n 
m o Z m 



oo m 
in in 
o in 



v© 



a. a o o 
< < m o> 
Z Z m oc 

00 o 
CN IN 
I CN 



o o c 
rN in 

-3" v© 



<r v© 

O 00 

m i 



o c o 
O in 
in oo 



in m 

CN v© 

m — < 



O O O 
o m 



-3- in 
rN o 

<r cn 



o o o 
\© <r 

IN o 



o <r 
cn <r 

V© CN 
I 



o o o 
cn cn v© 
m cn cn 



H CON 
— * CN 00 

in cn -h 

I I 



o o o 

CN vO CN 

On On CN 

m — i on 

CN -H ON 

CN -h CN 



c cx cx 
CN <c <c 
cn Z Z 

ON 

On 
CN 



C O 
CN O 
00 On 



IN O 



o o 
in on 
oc — < 



m oo 

N© ' 



o o 
<f m 

v© <t 



oo m 

CNJ " 



o o 
cn <r 

fN oo 



n© oo 

IN ^H 

m i 



o o 
m o 
O oo 



n© <J- 

ON I 



o o 

n© 
CN 

IN 

00 



o cx 

CN < 
CN Z 

On 
On 
CN 
I 



c o 
cn m 

On CN 



-© in 

O On 
CN ' 



O O 
v© O 
v© v© 



in — * 
in in 



o o 

— ' o 

CN <f 



in in 

m —i 

CN i— i 



o o 

00 CN 
00 n© 



in <r 
m vo 

m — i 
i 



o o 
m in 

CN On 



on <r 
i 



o o 

v© 
CN 

IN 

00 



CX CX 

<C < 
Z Z 



o o 

ON 

v© 



o o 

n© 

o 



oo 



o o 

<-* IN 

oo m 



in cn 
cn + 



o o 
n© m 
CN -3- 



m m 

ON —I 



c o 

vo In 
CN CN 



ON O 

+ 



o o 

v© 
CN 

In 

00 



o cx 
cn <; 

CN z 

ON 
ON 

CN 
I 



o o o o 
on <r in 

n© O v© 



m \© 

CN 00 



o o o o 
v© — n m 
o m oo 



<3- m m 

oo cn v© 

m —i 

+ + 



o o o 

00 IN N. 

-h on m 



-h cn in 
<r cn o 

— i rn cn 



o o o o 
— < m -^- 
in rN o 



oo -fl - <f 
o On <f 
m cn cn 



o o o o 
m oo m v© 
m o CN CN 



ON v£) oo in 
oo m cn oo 

CN CN — ' 



o o o o 

\D CN| vD CNI 

CN ON ON CN 

In O ■— I On 

oo m i— i on 

H H H N 

I + + + 



Cl D- d. 
< < < 

z z z 



o o o o 

00 V© tN 

m cn m 



m oo 
On o 



o o d. a. 
cn < <; 
<r z z 



o o a ex. 

CN| m < < 

m in z z 



o rn 
in m 

V© ' 



o o cx ex 
oo on < <! 
o- oo z z 



IN CNI 

o- o 

00 -H 



o o ex cx 
o o < < 
^h m z z 



-H V© 
IN CN 

I 



o o a cx 

<r in <3 <J 

oo m z z 

<r — < 

in cn 

cn cn 



o o o a 

cn n© v© <; 

CN r-i CN Z 

On \© m 

ON O ON 
NO-* 
I •> I 



u 
V 
cx 

a) 
o 



o 

O 
U 

CX -iH 



CC 



CO 
CO <D 



00 <V 
C 3 

e 

CD 

> 

0) 



UN 

o 

c 

bO OJ 

C B 

•h a 

jj o 

CO r-l 

U OJ 

oj > 

cx aj 



OJ 

e 
o 

CJ 

c 

CX T-t 

CO 

o ten 
to c 

J-J o o 

a) o *j 



QJ 
CC 
OJ ^n CO 

Emj/-N 
o o *© 
o • x o- 
c o co • 

1-1 >-• 4-1 o 

0) X i-H 

CO co X 



CD 

U 

X 
CO 



X 4-1 
CO 



0) 

OJ T3 
*-> CD 
CO [in 



l-i CO X) T3 

4-i a) 



O c/3 0i O Q h-l 



•o CX X 

c aj co 
a H 



< 



XJ >-J 

OJ O 



CO 






oo co 

CO o 

rH 

OO i-H CO 
C CO XJ 



OJ SZ 



CO CO CX CO CO o 
3 M CO O > 



U 4-1 14-1 

aj oj 

MHO) 

cx cx cn 
a) qj o 

Q Q hJ 



ai u 4-1 

cx bo s m 

O *J C MZ 

O -H CO 

0) Jxi > 

M M H 

•H O CO 

Q S CO 



cn 

o 

cj 

bO 

C 



CO 
)-i 
CD 

a 
o 



cn 

X- 

4-1 

c 
o 

6 
cn 
o 



• 


3 


CO 


U- 


4-1 


OJ 


CD 




CO 


T— 1 


cn 


CO 


co 


XJ 




•iH 


CD 


a 


t— i 


CO 


X 


o 


CO 




•H 


bO 


CJ 


C 


a; 


•H 


1-4 


^ 


a 


>-l 


OJ 


o 


o 


^ 


rr 


r\ 







• E 






(D --H 






m 






1-4 4J 






3 U 






o a 






C 1 






•H O 






m 






i-i 






CO •> 






CD 0) 






>N 3 






C 






CJJ QJ 






X. > 






4-i cd 






i-i 






c 




• 


•H 14-1 




c 


O 




o 


T3 


• 


•H 


01 4-1 


0) 


4-1 


CO o 


.—I 


CO 


c a. 


X 


•i-H 


QJ 


cfl 


O 


cx m 


o 


CD 


X — ' 


•f-4 


U 


OJ 


H 


CX 


4-1 


ex 


0) 


co co 


CX T3 


OJ 


CO 




H c 




cn 


X o 


4-1 


0) 


1-1 -H 





-o 


bC xj 


z 


3 


C QJ 




H 


CO -H 




O 


4-1 CX 


CX 


c 


C CD 


<H 


h-< 


W Q 


z- 


— ( 


n m 



17 



3487 84 



18 



TABLE A-ll. - Summary of discounted cash flow 1 



Year 


Net 
cash flow 


25-pct continuous 

interest rate 
discount factors 


Present 

worth of 

cash flow 


30-pct continuous 

interest rate 
discount factors 


Present 
worth of 
cash flow 


1984 


-$1,498,640 
143,290 
544,600 
744,590 
636,800 
581,420 
623,210 


NAp 
0.8848 
.6891 
.5367 
.4179 
.3255 
.2535 


NAp 
$126,780 
375,280 
399,620 
266,120 
189,250 
157,980 


NAp 
0.8640 
.6400 
.4741 
.3513 
.2602 
.1928 


NAp 
$123,800 
348,540 
353,010 
223,710 
151,290 
120,150 


1984-85 

1988-89 

1989-90 




NAp 


NAp 


2 1, 515, 030 


NAp 


3 1, 320, 500 



NAp Not applicable. 

discounted cash flow rate of return - 25 pet + 5 pet 

2 Net present value = $16,390. 
3 Net present value = -$178,140. 



f 16, 

W94, 



390 



530 



= 25.08 pet, 



US GOVERNMENT PRINTING OFFICE: 1986—605-017/40.057 



INT.-BU.OF MINES,PGH.,PA. 28289 



U.S. Department of the Interior 
Bureau of Mines— Prod, and Distr. 
Cochrane Mill Road 
P.O. Box 18070 
Pittsburgh. Pa. 15236 



AN EQUAL OPPORTUNITY EMPLOYER 



OFRC1AL0USINESS 
PENALTY FOB PRIVATE USE. $300 

] Do not wi sh to receive thi s 
material, please remove 
from your mailing list* 
| | Address change. Please 
correct as indicated. 



1 



u>V 







vv 










<a 




/X 









* o .Ay . i ' * 





« 







.£. ■ « ■• " A~ <*> * o » o J o, 

^ °JlH§l r ^ 



> v* * ' • °- "c* ,o v s ■ • • 

A* v *v - 




o > 

.0 v 



rr,- 1 ,o- 









^°* 



° * 

^ ^ ;-Ji& %/ :^fe;-, \. i c .*^«-. % v ^ 

^°* ^"^» ; ^^ -fife*/ **°<* : ^^»: ^°^ 






y . 









^0 X 







^ '*mS +*X 7W ^'X -.^y^j 






■ ^ v^v v : ^^ v^ f %°° %« 











: *b v^ 






o w o ' ■$ 

V , 

. r v*K* • 




















V. * » * o ° «<J> V 





■ .& .Wa' >. ^ * 
















> /> 












I: Si :111If: tS -^B" V -«^- "^o* .°W& "ov* .^jfl^*- ^-o* 






a . 



£*<*> 



oy :§m^* ^d* 





lV^ 









<, 







.** .*>B 



-^. « 




°... ^ /jrajgfe,'. V , <■ 










* ^ 



"V ■ • . v. » v 




LIBRARV OF 



CONGRESS 



•»»g894 2 






■ 



t 1 








































> ' 1 












1 Jfa 










■ 









